
class BootStrapForm:

    # 自定义类属性
    bootstrap_class_exclude = []

    def __init__(self,*args,**kwargs):
            super().__init__(*args,**kwargs)
            for name,field in self.fields.items():
                if name in self.bootstrap_class_exclude:
                    continue

                old_class = field.widget.attrs.get('class', "")
                field.widget.attrs['class'] = '{} form-control'.format(old_class)
                field.widget.attrs['placeholder'] = '请输入%s'%(field.label,)

#class Foo(BootStrapForm):
#    bootstrap_class_exclude = ['color']

#obj = Foo()